[TR] Push or Pull

[Dave1massey at cs.com]

In a message dated 10/23/2007 6:01:09 AM Central Daylight Time, 
DLylis at aol.com writes: 
> I am going to eliminate my fan on my 3A and install a 12" electric  fan.  
> Opinions have been offered as to push or pull.  Surprisingly, a  common one 
> is to 
> install as a pull because as a push the fan blocks too  much air flow.  In 
> my 
> opinion that is not accurate as the radiator  does not care which side the 
> blockage (if there is one) is on.  I would  prefer that the electric fan not 
> be 
> seen from inside the engine bay.  What  say those with experience in this? 
> 
If you are going to mount the fan right up against the radiator then I agree 
with your assessment.  But better results are achieved by spacing the fan a 
bit away from the radiator.  This allows the air to distribute across the face 
of the radiator for more effective cooling.  But this only works if you 
fabricate a shroud to direct the air flow through the radiator.  Here's some 
anecdotal evidence:

A friend with an MGA with a Buick 215 conversion was having trouble keeping 
cool at low vehicle speeds.  He had an electric fan mounted as a pusher.  Using 
the same fan he fabricated a shroud and mounted the fan a couple of inches 
away from the radiator and the difference was like night and day.

Putting this in context, there is more space in front of the radiator than 
behind so setting it up as a pusher makes the most sense if you were to go this 
route.

Dave Massey